1. Field of the Invention
The present invention relates to an explosive reactive armor for use in combat vehicles, and particularly, to an explosive reactive armor with a momentum transfer mechanism which is capable of providing a protection effect regardless of the incident angle of a threat including a right angle of incident threat.
2. Description of the Prior Art
In general, explosive reactive armor, as shown in FIG. 1, is a protection mechanism fixed to the exterior of a combat vehicle (e.g., an armored vehicle) by bolting or other means, for protecting the combat vehicle from an external threat such as the penetrator or jet of a warhead or the like. Referring to FIG. 2A, a prior explosive reactive armor 10 is installed at an outer surface 25 of the combat vehicle so as to form a slope angle inclined (α) with respect to the vertical and includes a reactive material 13 such as a high explosive charge filled within a casing between a front flying plate 11 and a rear plate 12. After an external threat 2 such as a bullet or a projectile makes an impact on the explosive reactive armor 10, if the threat 2 penetrates the front flying plate 11 of the explosive reactive armor 10 and arrives at the reactive material 13, as a result, the reactive material 13 is detonated. By the detonation of the reactive material 13, the front flying plate 11 and rear plate 12 of the explosive reactive armor 10 are flung in the counter directions shown by the arrows in FIG. 2B. Therefore, the intersecting position between the threat 2 and the front flying plate 11 moves along a line of the front plate 11 thereby forming a longitudinally shaped of a penetration opening 11′ as shown in FIG. 3. During this “sliding” on the front plate 11, the threat 2 is destroyed by degrees. Thus, when it arrives at the actual surface 25 of the combat vehicle 20, the momentum of the threat 2 has been already significantly dissipated, so that damage to the combat vehicle 20 is remarkably decreased in spite of the threat having impacted.
That is, when the threat 2 impacts on the front flying plate 11 of the explosive reactive armor 10, the reactive material 13 filled in the gap between the front and rear flying plates 11 and 12 detonates by the shock pressure generated during the impact, and then the front and rear flying plates 11 and 12 are flung in, the perpendicular direction to the explosive installation surface by the detonation energy of the explosive 13. During this progress, the front and rear flying plates 11 and 12 interact with the threat and destroy or disrupt the threat. As a result, a protection effect can be achieved. In such arrangement, a dynamic plate thickness effect may be referred to as a significant protection mechanism between the explosive reactive armor and the threat. Herein, the dynamic plate thickness effect refers to the effect achieved by continuously interposing an intact material across a flight path of the threat while the front and rear flying plates 11 and 12 fly and thus substantially increasing an effective thickness of the material. Most explosive reactive armors have been developed to provide such a protection mechanism.
However, it has been known that, when the threat 2 impacts on an explosive reactive armor 10 based on the dynamic plate thickness effect, the protection effect can be achieved only in case of having a relative slope angle (between the explosive reactive armor 10 and the threat 2) of more than a certain degree (e.g., a slope α of more than about 60°), and thus the protection effect is remarkably reduced when the relative slope is decreased. This is due to the phenomenon that, when the slope α is not enough, a middle/rear portion of the threat penetrates the front and rear flying plates 11 and 12 without any interaction through an opening formed by a penetration of the front end of the threat. However, when the explosive reactive armor 10 is mounted on a combat vehicle 20 such as a tank or an armored vehicle, the explosive reactive armor 10 may be impacted perpendicularly by a threat. Thus, it is vulnerable for failing to achieve the purpose of providing a protection capability.
Even in case that the explosive reactive armor 10 is impacted obliquely by the threat, i.e., at a slant, the protection effect can vary depending on the length of the threat. While initiating a movement of the flying plates 11 and 12, in case of a shaped charge jet or a penetrator having a relatively long projectile, the front portion of the projectile may pass through the explosive reactive armor 10 while only the rear portion thereof is disturbed by the explosive reactive armor 10. This mechanism can still achieve a protection effect. On the other hand, in case of an explosively formed penetrator (EFP) having a relatively short projectile, the entire projectile may pass through the flying plates before the flying plates sufficiently initiate their movement. As a result, there has been a problem that it is impossible to achieve the desired protection effect.